Charge coupled device for overcoming an output voltage difference between different shift registers

Abstract

A charge coupled device includes shift registers, a common transfer electrode, and a floating and diffusion layer. Clock pulses are applied to the common transfer electrode. In response to the clock pulses, the common transfer electrode outputs signal charges to the floating and diffusion layer at a time when the shift registers are not being driven. Therefore, there is no output voltage level difference between the different shift registers.

What is claimed is: 
     
       1. A charge coupled device for reducing an output voltage level difference between different shift registers, comprising: a plurality of shift registers;   a floating and diffusion layer connected to the plurality of shift registers for receiving signal charges transferred by the shift registers when driven and for converting the signal charges into voltage;   a common transfer electrode, located between the plurality of shift registers and the floating and diffusion layer, for receiving signal charges from each of the shift registers and for transferring the signal charges to the floating and diffusion layer; and   timing means for applying clock pulses to the common transfer electrode in a predetermined sequence in order that the common transfer electrode transfers the signal charges into the floating and diffusion layer while the respective shift registers are not being driven.   
     
     
       2. The invention of claim 1, further including an output electrode located between the common transfer electrode and the floating and diffusion layers. 
     
     
       3. The invention of claim 2, further including a plurality of common transfer electrodes located between the shift registers and the output electrode. 
     
     
       4. The invention of claim 3, wherein the number of common transfer electrodes is an even number. 
     
     
       5. The invention of claim 4, further including means for periodically applying a predetermined voltage to the floating and diffusion layer so that it is alternatively biased to a predetermined voltage potential and a floating condition as to its potential, the means for applying clock pulses being coordinated with the means for periodically applying a predetermined voltage to transfer the signal charges from each respective shift register only when the floating and diffusion layer is in a floating condition. 
     
     
       6. The invention of claim 3, wherein the number of common transfer electrodes is an odd number. 
     
     
       7. The invention of claim 6, further including means for periodically applying a predetermined voltage to the floating and diffusion layer so that it is alternatively biased to a predetermined voltage potential and a floating condition as to its potential, the means for applying clock pulses being coordinated with the means for periodically applying a predetermined voltage to transfer the signal charges from each respective shift register only when the floating and diffusion layer is in a floating condition. 
     
     
       8. The invention of claim 1, further including means for periodically applying a predetermined voltage to the floating and diffusion layer so that it is alternatively biased to a predetermined voltage potential and a floating condition as to its potential, the means for applying clock pulses being coordinated with the means for periodically applying a predetermined voltage to transfer the signal charges from each respective shift register only when the floating and diffusion layer is in a floating condition. 
     
     
       9. A charge coupled device for overcoming an output voltage level difference between different shift registers comprising: a plurality of first shift registers;   a floating and diffusion layer for receiving the signal charges transferred in the first shift registers when driven and for converting the signal charges into voltage;   a common shift register, located between the first shift registers and the floating and diffusion layer, for receiving the signal charges from the first shift registers and for transferring the signal charges to the floating and diffusion layer; and   means for driving the common shift register so that the signal charges are transferred to the common floating and diffusion layer while the first shift registers are not being driven.   
     
     
       10. A charge coupled device as claimed in claim 9, wherein the common shift register is driven by two different kinds of clock pulses, and the number of stages for one kind of clock pulse is one more than that for the other kind of clock pulse. 
     
     
       11. A charge coupled device as claimed in claim 9, wherein the common shift register is driven by two different types of clock pulses, and the number of stages for one type of clock pulse is equal to that for the other type of clock pulse. 
     
     
       12. A charge coupled device for overcoming an output voltage level difference between different shift registers, comprising: a plurality of shift registers;   a floating and diffusion layer for receiving the signal charges transferred in the shift registers when driven and for converting the signal charges into voltage;   first means, located between the shift registers and the floating and diffusion layer, for receiving the signal charges from the shift registers and for transferring the signal charges to the common floating and diffusion layer; and   second means for applying clock pulses to the first means in order that the first means transfers the signal charges to the common floating and diffusion layer while the shift registers are not being driven.   
     
     
       13. A charge coupled device as claimed in claim 12, wherein the first means consists of only one common transfer stage. 
     
     
       14. A charge coupled device as claimed in claim 12, wherein the first means consists of a plurality of common transfer electrodes, and the second means applies the clock pulses to at least a transfer electrode which is located immediately before the floating and diffusion layer. 
     
     
       15. A charge coupled device for overcoming an output voltage level difference between different shift registers, comprising: a plurality of first shift registers;   means for applying clock pulses to said first shift registers to drive them;   a common shift register for receiving the charges from the first shift registers and for shifting the signal charges through the common shift register;   a floating and diffusion layer for receiving the signal charges from the common shift register and for converting the signal charges into voltage; and   means for applying clock pulses to the common shift register so that the timing of said clock pulses to the common shift register is always different from that of said clock pulses applied to the first shift registers, wherein the common shift register transfers the signal charges to the floating and diffusion layer when the first shift registers are not being driven.   
     
     
       16. A charge coupled device as claimed in claim 15, further including a plurality of common transfer electrodes forming the common shift register. 
     
     
       17. A charge coupled device as claimed in claim 16, wherein the number of common transfer electrodes is an odd number. 
     
     
       18. A charge coupled device as claimed in claim 15, wherein the common shift register has a transfer channel that gradually reduces in width in the direction of signal charge transfer.